Palladium‐Catalyzed Selective Anti‐Markovnikov Oxidation of Allylic Esters

Aldehyde‐Selective Wacker‐Type Oxidation of Unbiased Alkenes Enabled by a Nitrite Co‐Catalyst

“…Researchers have exploited specific biased alkenes to circumvent Markovnikovs rule and produce aldehydes. [5][6][7][8] Unfortunately, the utility of this approach is inherently limited because the vast majority of alkenes are unbiased, and thus mere traces of the anti-Markovnikov aldehyde products are observed. [1d, 5, 9] A general aldehyde-selective Wacker oxidation would be a key advance in the field of anti-Markovnikov functionalization [10] because aldehydes are not only sought after products but are also versatile synthetic intermediates.…”

Aldehyde‐Selective Wacker‐Type Oxidation of Unbiased Alkenes Enabled by a Nitrite Co‐Catalyst

“…Prior to this work, contradictory reports have suggested that palladium nitrite complexes could oxidize alkenes through attack of either t BuOH or the nitrite ligand. Anti‐Markovnikov attack by t BuOH has been substantiated with specific substrates,7, 8b, 12b, 19 however it is unlikely to occur under the present conditions, as the aldehydic oxygen atom should not be derived from nitrite after t BuOH attack. On the other hand, definitive attack by nitrite salts has been demonstrated only in systems that exhibit high Markovnikov selectivity 20.…”

Regioselective Wacker Oxidation of Internal Alkenes: Rapid Access to Functionalized Ketones Facilitated by Cross‐Metathesis

“…In the classical Tsuji–Wacker oxidation of terminal alkenes, phthalimide and ester directing groups have been shown to direct an anti‐Markovnikov attack to form aldehydes from terminal alkenes 9. Strikingly, a recent report from Feringa and co‐workers demonstrated the inability of neutral palladium(II) complexes to oxidize internal alkenes 9b. Instead, internal allylic esters rearranged to the corresponding terminal alkenes prior to oxidation.…”